Tightening up the Turbo Waste Gate ?

Post by **charlyW** » 28 Mar 2010, 15:40

Today I got told of a simple mod for my 855 T5 that was to tighten or shorten the Waste Gate rod on the Turbo by 3 turns is this practicle/possible and or potentially any good or will it blow my engine to kingdom come ?

If it's a good mod how is it done and what am I actually tightening up or shortening?

final Question will I see any Benefit from this mod on my 97 855 T5 Auto? Maybe someone can give me insite to this modification please

Post by **matthew1** » 28 Mar 2010, 19:36

Modifying the wastegate rod, theory and practice. Good thread about this stuff. I put a few turns on mine about 10 years ago.

Post by **JDS60R** » 28 Mar 2010, 22:22

VADIS provides the adjustment procedure and proper setting for each car. You will find they all come set differently from the factory. I like to check the setting when buying a used car.

Just post which car you have and someone with VADIS will respond. If you set it at the factory setting the cars become lots of fun to drive.

You are setting the minimum boost level the turbo will be running at while the car is running with no gas pedal input. This amount of boost is always on. When you hit the pedal it then boosts up to its psi limit. For example - On some cars that produce 12psi max the wastegate setting is to hold 2 lbs of boost. This means when you accelerate from idle you immediately have 5psi of boost. If you turned it up to its max of 12psi you would have 12psi boost too soon and it would bend rods etc. Even if it doesn't do this the first time it will stress/destroy the engine soon.

As mentioned earlier going over stock setting will do bad things. At the proper setting you get great response , great mileage and great longevity.

Do a stage 0 by checking the turbo control valve's operation (usually not working up to spec), set the cam pulleys properly, replace the plugs, filters ,fluids and set the wastegate. These cars, properly tuned, running on top shelf synthetics are lots of fun.

Post by **JDS60R** » 28 Mar 2010, 22:31

Charly - here you go

For those with a PSi guage 1KPA = 0.1450377psi
so 12.5kpa = 1.812972psi

here is a KPA to PSI converter
http://www.translatorscafe.com/cafe/uni ... %5Bpsi%5D/

Post by **charlyW** » 29 Mar 2010, 03:52

It is a 1997 RHD 855 T5 B5234T engine Automatic Transmission

Post by **jblackburn** » 29 Mar 2010, 19:30

I did not quite 3 turns on mine, and it feels like a new car. I don't have a boost gauge, but it definitely picks up around 2000 RPMs now instead of the 2500 it used to, and while it still doesn't squeal the tires from a stop, it feels like it gets up and goes a lot faster. I think it's about the same at the higher revs, which is to be expected.

I wish the 5-cylinders were as spunky and free-revving as my old 4-cylinder cars were.

Post by **charlyW** » 30 Mar 2010, 12:07

Over the weekend I will be adjusting the wastegate as its slightly out of adjustment, waste gate isnt closing. To clarify I allow the waste gate to close after pulling off the small clip and unplugging the arm, take the pressure up to 4lb/psi till the wastegate opens then its adjusted or put two turns in from closed if I my pressue unit no longer works

Post by **MadeInJapan** » 30 Mar 2010, 13:41

It should close all the way even if the rod isn't adjusted all the way. Do you see where it swivels? Is that part pushed up? If it is, pound it down- it should be flush with the turbo housing- if it's not, this might be the reason it's not closing. Post back if you don't understand...I might find a picture of what I'm talking about.

Post by **JDS60R** » 30 Mar 2010, 14:05

The wasgate valve and actuator each have to do their part. While setting it the wastegate valve must be fully closed . To achieve this you remove the rod and you should be able to open and close the valve by hand.

Now that the valve and the actuator are seperate you apply the proper psi/kpa to the acutator. Leave the pressure on the actuator and try to place the actuator rod back on the valve without moving the valve. If it fits you were set correctly. If it does not fit perfectly ( perfect =valve closed and actuator rod slips on valve without moving valve from its closed position) then correct it to fit perfectly by turring the rod "end" until the hole in the rod, and the pin it goes on, line up perfectly.

Important Hints
Release the holding nut on the actuator rod properly. You will need to hold the rod stable to release the nut and turn the end.
Do not allow the rod to turn. Mark the top of the rod so you can see if it is turning. Hold the rod with pliers. Turning the rod can damage some actuators.

Once the rod and valve are together again you should release your pressure and then reapply the proper amount. Watch the valve. It must not move until you go slightly over the vadis pressure. If it does move below the vadis pressure then you have set it incorrectly.

The idea here is to assure the wastegate valve remains closed until the wastegate experiences the preset pressure in the VADIS doc above. Anything higher than the Vadis pressure and the wastegate valve shoud move/open.

I have a magnetic dial gauge I use to monitor the wastegate valve action but if you look closely you can see it as the pressure rises to the correct amount. The rod end is usually bigger than the shaft it goes on. I leave off the retaining pin and watch the slack disappear while I add the pressure. I then go and recheck my findings with the dial guage. I want to kow what pressure it opens at. It should open just above the vadis setting. So if yours is 2psi then by 2.25 psi your valve should have moved

You will want to apply/remove the pressure several times just to be sure you have it right. If your setting is 2psi then the wastegate shold be closed at 2psi but open by 2.1 to 2.25psi

Post by **charlyW** » 31 Mar 2010, 02:59

JDS60R wrote:The wasgate valve and actuator each have to do their part....

Thanks thats what I thought it read, Will get to adjusting mine over the weekend as the wastegate isnt closing at all on mine and I need to dig out a pressure guage out of the shed.